Power brake mechanism



Feb, 23g, i932.

POWER BRAKE MEGHANISM Filed March l, 1928 2 Sheets-Sheet l v I" C) 70 7a 4 ENE/NE 73 MAH/FOLD 6.4 90 A "E" ,al Gu J Jy /06 los, 1v1/vanto@ 2 ya A636?? Feb 239 m32. G, P, ,wwwv 1,846,081

POWER ERAKE MECHANISM Filed March 1, 192e 2 sheets-sheet 2 gva/vanto@ we c,

Patented lilith., 23, 1932 PATENT OFFICE lWIEIR BRAKE MECHANISM Application tiled March ll,

this invention relates to hralre operating rneohanisin and has heen designed p artion larly as an improvement in the operating; mechanism *lor a ooinhined mechanical and ll llnid pressure loralre lor inotor vehicles.

ln lrnovvn systems ot this hind, it has heen proposed to supplement the inanual etlort of the operator hy :duid pressure rendered ellective to apply the hralre hy rneans oli a lll valve controlling the pressure condition, the valve containing inovahle parts actuated hy the pedal or lever need loy the operator in applyinga the hralre mechanically.

lin ohject oi2 this invention is a siin Jditied .lll arrangement ot these lrnovvn parts. l s another oliieotT the simplification is attained without the sacrice oit certain characteristics ol earlier 's' sneh as the division oll the applied elliort, and the reaction on the pedal lll' ol the added supplementary pressure. ills another and ilnportant ohject, the invention contemplates the niountinp; oli the control valve on the pedal, therehy avoiding' all the eonneotin "arts het "een the pedal and valve i ich a a corninonly used 'when the valve is otherwise lr ated. lflther olrleots and ad he understood ilrorn a readinin fina; l'ull description and 'liront an o he ancoinpanyintg1 drawings.

llll the dra vinger 9ure l is an elevation ol iny improved lara operatinp;I nieolianisrn tpplied to a vehicle lllipgnre a section through a prelerred liorln ot valve l lligrnre To is a vievv ol the valve in end elevation, the vietv heine; partly in section and on line lim-Il ol llignre E;

ldignre ll is an elevation ol inoditled ltorrn; and l llinine a section on line tif-5 ol lligure l.

Figure a section on line tlm@ oli lligure l..

lle-terrine' hyreference characters to the W dravvinos. lirst to Figures l to 3 inclusive, *l nunieral l represents a pedal pivotally located on the vehicle as is the usual hralre pedal of a motor vehicle. lllnnieral 9 represents the lever 'liuloruni which may hein any convenient n positionheneath the 'lloorhoards rllhe pedal has an upper arm ll eatendingr through the 1928. Serial No. 58,293.

lloor hoard Where it is provided at its er-` trernity with a toot pad 13. The foot pad is movaloly related to the pedal proper instead ol being liXed to the pedal, as is customary. 'lo provide a guided movement, the end ol the pedal has a recess l5 receiving a tubular stem portion 17 projecting trom the pedal pad 13, the stem 17 slidably guided in the recess l5. The stern ll may loe slotted as at 2l and a set screw 23 carried by the end ot the pedal may enter the slot and he positioned to at times engage the inner end thereof.. By this means, rotation ot the pad relative to the pedal is prevented and its outward movement is liinited. 'llhe angular arin ll is :turther longitudinally apertured as at 'i9 lor slidn ahly mountingr a reciprocating rod 25 leaving` a head 2l vvithin the recess l5 and also Within the inturned end 16 ot the tubular stern ll oil" the pad. ldetvveen head @l and the pedal pad l?) and located with the hollow stern is a relatively heavy compression coil spring 29. lletvveen the in-turned end of the tubular stern l? and the hottorn ol' therecess 'lli is a light coil sprint,w 3l.

ldivoted to the angle portion olf the pedal. loeneath the lloor hoard as at 33 is a loe-ll oranlr lever 35 having1 a short arin 37 errtendingl lengthwise of the arin 39 ol the pedal 7, vvhich arm lies heneath the door hoard. This arin ljl'l is engaged hy the lovver end ot rod 2li. ylhe other arm ol loell cranlr, arno lll, has a plurality oit apertures represented hy ntl-- ineral d@ lor adjnstalolv connecting to the hell cranh one end ol a rod l?) parallel to arrn 89. rllo the lower end ol arrn 39 near the tuloruin oli the pedal is a loraelet l5 secured loy tasteninp; rneans lll". 'lo this bracket is secured a lluid pressure control valve designated as an entirety hy numeral 49 and rnore particularly shown Vin litigare Q. This valve contains nuovahle parts Which are actuated hy the operator through the instrumentality oli' the pedal pad in its movements relative to the pedal. lhe inwardinovement oli the pedal pad as it o0rnpresses spring 3l rnoves the head 2"( oit rod 25 through the agency of spring 29. This 1novement ot head 2'? and rod 25 rotates the hell crank and through the loell crank withdraws rod d3 troni the valve lll).

lill

'lli

till

The valve is composed of a head portion 51 and a valve body 53, the body and the head being secured together by suitable fastening means 55. The head 51 has two openings 57 and 59, as best shown in Figure 3. rIhe opening 57 extends to the middle of the head and the opening 59 extends only part way toward the middle. Secured to the head as by being clamped thereto by fastening means 55 is a sylphon bellows 61. The other end of the bellows carries a movable valve seat 63. The valve seat may have a hollow stem 65 slidable in a reduced part 67 of the valve body 53. A set screw 69 in a slot 71 may serve to limit the movement of the movable valve seat. Valve rod 70 is guided in an opening 73 in the reduced outer end of member 53 and in a recess 75 in part 51. The head 51 is formed with a valve seat 77 engaged by a valve 79, the valve 79 being slidably mounted on the rod 70. Within a recess 81, which is at the inner end of opening 57, in the head 51 are nuts 83 to at times engage valve 79 and raise said valve from its seat 77, this action being effected by an outward reciprocating movement ofrod 70. As will be seen from Figure 1, the rod 70 is terminally connected with rod 43. Rigid with or secured to rod 70 is a valve 85 positioned to engage at times'the movable seat 63 carried by the bellows. This engagement is made when rod 70 is moved outwardly and to the right, as shown in Figure 2. A coil spring 87 encircles rod 70 and is in abutment with valve 85 and operates to push valve 79 against its seat77. A coil spring 89 also encircles rod 70 and is located between an abutment 91 rigid with the rod and the inner reduced end 90 of the valve member 53. From Figures 2 and 3, it will be seen that opening 57 communicates with the bellows through the valve 79, when open, and that opening 59 is at all times in -communication with the interior of the bellows. A conduit 95 connects the opening 59 with a power operating cylinder 97 on that side of the piston in the cylinder remote from a rod 98, which connects the piston of the cylinder with an arm 99 formed preferably as an integral part of the pedal 7 Another pedal arm 101 is for connection to a brake or the brakes through any preferred sort of hook-up by means of a rod 102. lith reference again to the valve it should be noted that the body member 53 is provided with one or more openings 104 and that a cover member 106 is positioned over the end having the openings 104. Between the part 53 and the cover member there may be an air cleaning material 108, such as coarse hair.

The source of power is preferably the suc.- tion obtainable from the internal combustion engine of the lvehicle and is rendered available bythe opening of the suction valve member 79 of the valve 49. Such opening causes` the motor suction to withdraw air from that Leeaoeji side of the piston in cylinder 97 remote from the connecting rod 98. l The air on the reverse side, being at atmospheric pressure, is therefore effective to push the piston toward the left as in Figure 1, and rotate the pedal clockwise and apply the brake by means of the rod 102.

The operation may be further described and it is substantially as follows As pressure is applied to the pedal pad, this pressure is transmitted through spring 29, head 27, rod 25, bell crank and rod 43 to the valve 49. The rod is thus pulled outwardly, valve 85 engages its seat 63 and a continued movement of rod 70 expands the bellows and opens suction valve 79. The motor suction then operates through the valve upon the power cylinder, as previously described. A part of the pedal pressureis used in so operating the auxiliary power mechanism. The other part of the pedal pressure is positively actuating the brake through movement of the pedal. The division of power is dependent upon, or measured by the extent to which spring 31 is compressed. Any yielding of spring 31 permits the pad to move relatively to the pedal and to push the rod 25 and cause the suction brake to operate. The pedal pressure is, therefore, divided, one part applying the manual effort directly and the other part operating the suction valve. In some earlier forms, when the equivalent of valve 49 was located elsewhere than on the pedal and connected to the pedal by operating linkage, the rotation of the pedal by the fluid pressure means caused the pedal movement to react on the valve and tended to hold the suction valve member open. That construction also interfered with the proper release of the suction brake, and it was found advisable to so arrange the linkage between the power cylinder and the brake that it should not operate through the manually operable pedal. By locatingvthe valve member rigidly with the pedal, such a reaction upon the valve is avoided. The valve is, however, a true reaction valve as will be readily appreciated. As the suction increases in the cylinder, it also builds up in the valve bel-lows. The valve chamber outside the bellows is open to the air and the air tends to collapse the bellows and close the suction valve 79. This action is, of course, resisted by the tension of rod 70. The pull upon-rod 70 caused by the unbalanced condition within the valve reacts through rod 43, bell crank 35 and rod 25 upon the pedal pad. This reaction does not necessarily lift the pad as the rod moves owing to the presence of spring 29. The spring 29 gives evidence to the operator as it becomes compressed of the extent of supplementary force being exerted by the suction brake.

It will beunderstood that the arms of the bell crank may be varied to produce a de- 

